The present invention relates to an electronics housing and also to a method for producing an electronics housing.
A generic electronics housing is configured and provided for the accommodation of at least one electronic component in an interior space defined by the electronics housing. In this connection, the electronics housing exhibits at least one pressure-equalizing element which enables an equalization of pressure between the interior and the exterior of the housing. Accordingly, in particular depending on the place of deployment of the electronics housing, the latter may under certain circumstances be exposed in operation to extreme fluctuations of humidity and temperature. As a result, a relatively high rise in pressure or a partial vacuum may occur in the interior of the housing, which may lead to damage to the electronics housing and to the subsequent uncontrolled penetration of moisture.
Solutions are in fact also known from practice, in which the electronics accommodated in the electronics housing are potted and the housing is completely impervious, or in which the electronics housing is equipped with a device for selective water management. However, a completely sealed housing entails the disadvantage that at an excessive internal pressure a housing wall will fail at a weak point, so that water can then penetrate through this into the interior space of the electronics housing. In addition, disadvantages may arise with this solution, in particular by virtue of the fact that additional costs arise as a result of the potting of the electronics, and the differing coefficients of thermal expansion between electronic components and potting material may result in a shearing of electronic components. In the case of a device for selective water management, the penetration of water through a macroscopic opening is prevented, thanks to an appropriate structural design (for example, in the form of a snorkel). But in this case the danger regularly exists that in the case of an unfavorable route the water nevertheless penetrates through the macroscopic—that is to say, comparatively large—housing aperture.
Against this background, a pressure-equalizing element in the form of an air-permeable but water-impermeable diaphragm is known, for example from DE 37 16 912 A1, which covers a housing aperture. Via the diaphragm, an exchange of air and water vapor is consequently made possible, but at the same time the penetration of water into the interior space of the electronics housing is prevented. Ordinarily, diaphragms of such a type are glued to an edge of the housing aperture or are fixed thereto by means of ultrasound.
From DE 10 2011 121 716 B3 it is known, furthermore, to mount a gas-permeable but liquid-impermeable diaphragm on a housing aperture by means of a collar contour surrounding the housing aperture. In this case, with the aid of the collar contour which is locally interrupted over its periphery, it is ensured that no water and/or particles of dirt can collect in the region of the diaphragm.
Nevertheless, in the case of electronics housings that provide for an equalization of pressure between the interior and the exterior of the housing via a diaphragm, a wetting of the diaphragm by water or surfactants or even a clogging of the diaphragm, in particular by dirt, regularly occurs, by virtue of which an equalization of pressure is considerably restricted or even completely prevented. Surfactants settling on the diaphragm have the result, for example, that the diaphragm becomes permeable to the water remaining on it, since the surface tension is lowered and hence the contact angle between water droplets and diaphragm becomes smaller. Water then penetrating into the electronics housing, or condensed water arising therein, results in damage to the electronics. Furthermore, by virtue of external influences such as temperature fluctuations and/or humidity, the at least partial detachment of the diaphragm may occur, and hence a loss of the impermeability to water in the region of the housing aperture.